Here are the QR codes for the Oval AND Shiny charms!
Left is Oval, right is Shiny!
To get them, stand outside of the pokemon center, and with your game still on, exit to your 3ds home screen.
Then, activate the camera by pressing L+R, and click on the little QR icon on the bottom left on the touch screen.
Scan one of them, and it will ask you if you want to open your browser, so click yes and open the site and wait for it to crash. And error message will be on the home screen, just click ok and return to your game.
Head into the pokemon center, and you’ll see a delivery girl. Talk to her to get the charm of your choice!
(If it doesn’t work at first, make Sure you clean your browser history and cookies!)